How have new "space age" wires changed orthodontics?

The nickel-titanium alloy was originally engineered by NASA to automatically activate antennae or solar panels of spacecraft orbiting into the sun's rays. Today, the archwire materials used in the orthodontic treatment are no longer limited to stainless steel. They can be alloys of nickel, titanium, copper, and other metallic elements, and some of the wires have shape memory effect. These types of wire exert a steady, gentle force on the teeth, so that the tooth-moving process may be faster and more comfortable for patients. As a result, the time period between visits can be extended and the number of appointments needed to make adjustments to the wires can be reduced.  more